In recent years, there has been considerable interest in the use of computer-mediated environments as assistive technologies for rehabilitation or learning purposes. Much of this interest has revolved around virtual reality or augmented reality systems, a type of computer-mediated environment that generates artificial environments within which the user interacts.
While not necessarily immersive, virtual systems typically plunge the user into a virtual environment where he or she can manipulate virtual objects. Some examples include role-playing virtual environments for adolescents with autism spectrum disorders, virtual reality play interventions and spatial training for children with cerebral palsy, multimodal environments for cognitive rehabilitation, a virtual maze for the assessment of spatial knowledge in teenagers with mobility impairments, and a virtual acoustic space for sensory rehabilitation of children with congenital blindness. These environments have demonstrated potential to improve social participation and enhance specific motor skills in individuals, while maintaining interest and motivation. Part of the appeal of such environments as an assistive technology lies in their unprecedented precision in controlling complex stimuli within a test environment, their ability to provide varying levels of environmental interaction, and the early evidence of skill transfer to real world tasks.
Prior art solutions in this field are known, for example, U.S. Pat. No. 5,534,917 for a “Video Based Image Control System”, issued to Very Vivid Inc. ('917). '917 discloses building a model of a background that is placed behind a target object, capturing the target object by means of a series of video images that include the background, and detecting motion of the target object analyzing the video images in a digital form, pixel by pixel, by applying threshold values that determine motion.